Repository-circuits
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In this project, you will make a simple 3-stage low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator with amplifier. You can connect the circuit to the an electred microphone or amplified.... -
This 2 Watt FM transmitter will provide 10km range in good weather conditions. Use dipole antenna for maximum range. Transmitter can be tuned between 88-108 MHz with c5. BB204 could be replaced with conventional led (big) with reverse bias (no light given in.... -
This is a simple 30V volt meter using PIC16F676 micro controller with 10-bit ADC (analog to digital converter) and three 7 segment LED displays. You can use this circuit to measure up to 30V DC. The possible applications are on bench power supply or as a.... -
This little broadcast FM transmitter has 500mW of RF output power and runs of 12-15V battery or power supply. DC whose signal modulated by FM using four transistors. Transmitter includes four transmitter stages and draws around 100-150mA of current. Using.... -
60MHz Frequency Meter / Counter measures frequency from 10Hz to 60MHz with 10Hz resolution. It is extremely useful bench test equipment for testing and measuring frequency of oscillators, transmitters, radio receivers, function generators, crystals, etc..... -
Here is a circuit for simulating breathing / pulsing LED with the 555 timer chip. It became very popular and i received many comments and emails with people that made this circuit and worked fine, as well as comments with people that had troubles converting.... -
This Voltmeter Ammeter was designed to measure output voltage of 0-70V / 0-500V with 100mV resolution and 0-10A or more current with 10mA resolution. It is a perfect addition to any DIY laboratory power supply, battery chargers and other electronic projects.... -
Rectifier bridge voltage. See U2 element you used data sheet to know about maximum voltage it can work properly. On the other hand the minimum voltage on that pin mustn`t drop bellow c. a. 9V, or 6. 5V if low drop type U2 and U3 voltage regulators were used..... -
This is an excellent Hi-Fi Stereo PLL FM Transmitter, the audio source can be the computer, sound card, game consoles, CD, DVD, MP3, stereo mixer for stereo audio signal modulated emission transmission, the board also contains two mic amplifier, with the.... -
FT232RL USB to Serial UART (TTL) Adapter is a simple and inexpensive way to connect PIC, AVR or ATMEGA MCUs to a PC or Mac via USB connection. FT232RL is an impressive chip because it implements full v2. 0 USB protocol, needs no external crystal, has.... -
This digital voltmeter is ideal to use for measuring the output voltage of your DC power supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199. 9V with a resolution of 0. 1V. The voltmeter is.... -
This is a high fidelity external USB Soundcard / USB Headphones project that can be built for your PC or Mac. It is based on the latest PCM2706 IC which functions as a high quality, crystal clear 16-BIT Stereo DAC. It is a single chip digital-to-analog.... -
This Phone FM transmitter connects in series to your telephone line and transmits the telephone conversation over the FM band when you pick up the telephone handset. Transmitted signal can be tuned by any FM receiver. The circuit includes an "On Air" LED.... -
AM radio built around 555 timer chip. The only active device (silicon, germanium, or otherwise) is the LM555. The tuning is accomplished with an inductor and a capacitor, and the LM555 acts as an AM demodulator and class-D power amplifier to drive the.... -
Automatic battery charger automatically starts the charging procedure when battery voltage drops below a certain predefined value and stops after the voltage has risen above the maximum allowed value. Setup can`t be easier, just connect two alligator clips.... -
This is simple to build AVR programmer for Atmel microcontrollers from AVR family. The microcontrollers must support serial programming. AVR programmer is connected to a PC through the RS232 serial interface and can be used with the PonyProg or Avrdude.... -
This simple tone control (bass & treble control) can be used in may audio applications. It can be added to amplifiers, used as a stand alone control module, or even built into new and exciting instruments. It uses NE5532 IC but other ICs such as LF353 or.... -
This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery..... -
Not thrilled with how a computer soundcard drove my 32ohm headphones so I decided to build myself class-A mosfet headphone amplifier. As with most of my projects, the goal was to keep it simple, keep cost down and try use some salvaged parts. This is a.... -
Four button RF remote is used to turn ON / OFF four different devices independently. Any of the four outputs can be configured to work independently in either toggle or momentary mode. Outputs are buffered by BC549 NPN transistors and can drive low voltage.... -
This is simple 3-digits digital volt meter.PIC16F676 used to read analog signal(voltage) and display the value on 3-digits 7-segment. You can apply similar principles to measure DC current with parallel R shunt.. -
As shown in the schematic, temperature sensor of our electronic thermometer is LM35DZ. There are some kinds of LM35 IC, since it is cheap and easy to find we used LM35DZ in our project. It measures from 0?C to 100?C with a very linear output graph.For one.... -
The amplifier has exactly the same architecture as TX500 with the difference that TX300 has only one stage variable VHF amplifier. It is a cute schematic that was made for all of you who wanted something even simpler than TX500 and with not as many necessary.... -
The TX500 is a simple to build 500mW FM Transmitter. It consists of three blocks; modulator / oscillator, two stage 500mW VHF amplifier and LED based power meter. The TX500 allows to transmit audio signals to FM band at frequencies from 88 MHz to 108 MHz..... -
This tiny receiver is not much bigger than an AA cell. It is powered off two LR44 button cells, which are expensive and I assume wouldn`t last terribly long. I`ll be on the lookout for LR44`s at the markets and $2 shops now that I`ve got this radio! As with.... -
This project is a FM Radio based on TDA7000 and LM386 integrated circuits. What is unusual about TDA7000 IC is how it operates. It is a proper FM superhet receiver, with the usual local oscillator, mixer, IF amplifier, limiter, and phase detector. The.... -
Here is the circuit diagram of the simple FM transmitter using a transistor. Great performance or range is not guaranteed here, because this is an elementary design. General purpose radio frequency transistor BF 494 (Q1) is used here for obtaining FM.... -
This FM transmitter is about the simplest and most basic FM transmitter it is possible to build and have a useful transmitting range. It is surprisingly powerful despite its small component count and 3V operating voltage. It will easily transmit over 300.... -
For measurement purposes in the electronics laboratory is needed again and again signals of different frequency and waveforms. A common function generator provides sine, for example, triangular and square waves. The frequency must be adjustable and at least.... -
This is an article about my new PCB design for CMoy headphone amplifier. Main feature is that the new PCB fits exactly to the classic Altoids tin-can. This new CMoy incorporates moreover bass-boost circuit and constant current charger for 9V battery. P1 is.... -
This device is designed to measure the torque in an automobile drive shaft and provide an output to a vehicle data recording system or a portable computer via an RS-232 interface. The received data can then be combined with RPM measurements from the data.... -
Build your own Accurate LC Meter (Capacitance Inductance Meter) and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils and inductors. LC Meter can....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is.... -
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to.... -
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This.... -
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the.... -
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,.... -
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the.... -
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power.... -
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
Popular Circuits
This circuit features an intermittent siren output and automatic reset. It can be operated...
LM13700 VCAs are used in a configuration identical to that shown in the Nat Semi data sheet that...
This circuit provides complete speed control over car"s windshield wipers. They can be slowed...
This is one of the most accurate and simplest LC inductance / capacitance Meters that one can...
This project is currently output two PWM signals but can be extended to many PWM signals very...
FM transmissions can be received within a range of 40 km. If you are in fringe areas, you may get...
This circuit alarms whenever someone cross the Laser beam transmitted from a LASER. The output of...
This section will list several projects which will allow you to build your own RF design test...
As shown, the long wire current loop transmission will be introduced radio frequency (RF)...
By the photocell photoelectric tracking circuit configuration, with two similar performance as a...